This program of research investigates a theoretical model of the determinants of depressive mood and psychological distress among adolescents, involving a departure from traditional intrapsychic conceptions. One major hypothesis is that the psychological orientation of introspectiveness--the tendency to think about oneself and one's feelings--causes psychological distress and depressive mood. A second major hypothesis is that discontinuities in adolescents' lives caused by physical maturation, school transitions, family crises, and stressful life events, increase the tendency to introspect and experience depressive moods. This theoretical model will be tested separately for different sex, race and ethnic groups to determine if it can account for the well-known gender difference in depressive mood which develops during adolescence. A longitudinal study is planned which will follow 7th, and 9th grade cohorts for three years, and an 11th grade cohort for two years. A total of 1,050 adolescents will be recruited through three diverse public school systems to insure a heterogeneous sample, and will be surveyed with a questionnaire developed especially for each age group. Parents of half the student sample will be interviewed by telephone each year of the study to collect important data on parental distress, parental introspectiveness, and the quality of the parent-adolescent relationship. A subsample of 140 students high and low on introspectiveness, and chosen to represent each sex and age group, will be interviewed intensively to validate the questionnaire data, and add interpretive depth. Both cross-sectional and longitudinal data will be analyzed with multivariate structural equation methods. If correct, this theoretical model will have implications for designing new treatment interventions. For introspective adolescents, traditional intrapsychic counseling may focus attention in a manner that exacerbates problems. These adolescents may benefit more from counseling which sets short-term tangible goals and teaches active coping strategies, or from school and community programs which engage attention on useful activities and block unproductive or obsessive introspection.